The specific aims to be addressed in this study are: 1) To estimate the differences in bone mineral density (BMD) at the hip and lumbar spine between 128 Caucasian and 128 African-American women with lupus and a comparable control group matched by age, race, and menopause status; 2) To determine the association of lupus risk factors with low BMD in women with lupus, after controlling for traditional risk factors for low BMD; 3) To follow the subjects entered in the cross-sectional study over a two year period in order to estimate the difference in the rate of bone loss at the hip and lumbar spine between women with lupus and a comparable control group matched by age, race, and menopause status; and 4) To determine the association of lupus risk factors with increased rates of bone loss in women with lupus, after controlling for traditional risk factors for low BMD. The hypotheses to be examined in this study are: 1a) Women with lupus have lower BMD at the hip and spine than matched controls; 1b) the negative effect of lupus on bone mineral density at the hip and spine is greater in Caucasian than in African-American women; 2a) Traditional risk factors for low BMD (nulliparty and menopause status, irregular menstrual cycles or premature menopause, avoidance of oral contraceptives and/or hormone replacement therapy, lower physical activity level, and decreased vitamin D levels) are associated with lower BMD at the hip or lumbar spine in women with lupus; 2b) lupus risk factors (greater disease activity, greater disease severity, higher corticosteroid burden, use of anticonvulsant drugs, and the presence of renal disease) are associated with lower BMD at the hip or lumbar spine in women with lupus, after controlling for traditional risk factors forlow BMD; 3a) Women with lupus have accelerated bone loss at the hip and spine during two additional years of lupus disease compared with matched controls followed for two years; 3b) the effect of lupus on the rate of bone loss at the hip and spine is greater in Caucasian than in African-American women; 4a) Traditional osteoporosis risk factors (mentioned in 2a above) are associated with accelerated bone loss in women with lupus; and 4b) lupus risk factors (mentioned in 2b above) are associated with accelerated bone loss at the hip or lumbar spine in women with lupus, after controlling for traditional risk factors for low BMD.